As South Australia's population continues to age, the issue of a youth "brain drain" has been debated by party leaders in the state election — but is the flow of young people away from the state an urgent issue?

Key points:

Number of people leaving high by historical standards, but not as bad as past recessions

According to the latest Australian Bureau of Statistics data, in 2016 South Australia lost 6,900 people in "net interstate migration" — the number of people leaving the state versus the number of people coming in.

Of those, 3,260 were people aged between 20-34 years old.

But despite recent debate, experts say the loss of young people from South Australia is nothing new.

"The desire is to keep people here, but the reality is this state has always seen people move on for other opportunities — some do come back, but it doesn't counteract those that are leaving year-by-year," said Debbie Faulkner, senior research fellow at the Centre for Housing, Urban and Regional Planning at the University of Adelaide.

In the past, increases in people moving interstate occurred after the global financial crisis in 2008, and after the 1990–91 recession.

"We lost manufacturing jobs, corporate headquarters left the state — it had a big effect," said Anthony Kosturjak, senior research economist with the South Australian Centre for Economic Studies at the University of Adelaide.

He said net interstate migration losses were relatively high by recent historical standards — effectively more than doubling between 2014 and 2016.

"They are not quite as bad as we saw during the mid-1990s in the aftermath of the recession and state bank crisis, but they are not that far off," he said.

"The earlier losses peaked at 7,845 persons in 1995, which compares with a net loss of 6,900 persons in 2016.

"Of course, the overall population is higher now so the most recent losses are not as bad in relative terms."

Mr Kosturjak

said there has been a corresponding increase in South Australians in their 20s and 30s leaving the state.

"They are typically the people who are most willing to leave because they are early in their careers, it's easier for them to move and they might not have children," he said.

Employment opportunities in Melbourne and Sydney

Katie Botha, a consultant psychologist who has been living in Sydney for a year, said she moved after graduating from university to make six years of study worthwhile.

Ms Botha contrasted her friends in the health industry, who have stayed in Adelaide, and those in law, finance and marketing who have moved for reasons similar to her own.

"I want to be able to work in the most competitive environment as possible in my industry, and that means having to seek out business, and the big clients, and where all the head offices are: which are Sydney or Melbourne," she said.

Alice McCormack, a university project coordinator in Melbourne, moved when she could not find a job after working overseas for a year.

"I wasn't really able to get any traction in terms of finding something that was the right fit for me, in that I've had five years' experience — there were a lot more entry-level roles, or people who were quite senior," she said.

Ms McCormack said many of her friends in Melbourne were Adelaideans who have all had to move for the same reason.

"They also wanted to have interesting, fulfilling roles that just weren't available in Adelaide," she said.

Mr Kosturjak said a number of factors had resulted in increases in interstate migration across all age groups in recent years.

"We've gone through a real period of heightened structural change over the last couple of years with the loss of manufacturing jobs and some people have taken the opportunity to start afresh in other states," he said.

"But it was also a period of just general weakness in terms of full-time employment growth as well."

'A rising tide lifts all boats': Improving economy could help

Mr Kosturjak used the example of interstate migrants flowing to Western Australia during the mining boom, and away from Western Australia when it finished.

"Ultimately, population movements are very responsive to changes in economic performance," he said.

"Moving back to Adelaide is definitely on the cards for me — it just means having to establish my career, make a name for myself in the industry, before I can move back," she said.

Ms McCormack also sees herself staying in Melbourne for the foreseeable future.

"I'd love to go back to Adelaide — I grew up there, my family's there, I really love it — but it's all well and good to say that but if I can't pay the bills, it makes it a little bit challenging to go back there."